Question: Which element has a larger radius?

[Collin Li]

Of course

It's also important to provide security for those who come here and panic because they are learning things at this late stage.

[principe]

The answer lies in the fact that for elements other than the noble gases, you are measuring metallic or covalent radius, which is measured when they form metallic or covalent bonds. For nobles gases, we measure their van der Waals(Dispersion forces) radius, where they are bonded less tightly and closely to each other.

To explain this simply, when non-group 8 elements form metallic or covalent bonds, their electron "cloud" gets squashed, and since the atomic radius measures the distance from the nucleus to the center electrons that participate in the bonding, they are smaller than the noble gases in their period.

Ohh I see, that clears things up. It's better to understand something than to just leave it and never figure out the idea behind it. Hey it might be useful in the future  

[ninwa]

thanks for that hifer =]

[ezflow]

Yeah thanks hifer... for making me look stupid! Hehehe.

Good luck for Chem everyone! Everyone shall all triumph.